Delimbers presently are constructed in several different versions. Some delimbers have cable drives for driving the delimbing boom and some have chain drives. Some delimbers employ a single section or mono boom and others employ a multi-section or telescopic boom. Because of the different versions of delimbers used, it is expensive for a manufacturer to provide a full range of delimbers and many do not.
Delimbers are also presently constructed to employ a fixed displacement hydraulic motor to operate the cable or chain drives which move the boom. This arrangement is relatively simple and inexpensive. The hydraulic motor is sized to have the delimber able to handle the size of the tree to be normally harvested and is a compromise in the power required to lift the tree and the speed required to delimb it. Because of the compromised design, the delimber is slow in picking up and handling trees larger than the normal size to be delimbed. In efforts to increase the speed of operation of the delimber when handling large trees, the operator often increases the operating pressure of the hydraulic motor over its designed limit and this can lead to failure of the motor.
Delimbers that employ cable boom drive means sometimes fail due to stress. This is, in part, due to the fact that the cables are not long enough to handle the loading. The cables can also fail if they are not properly tensioned. The cables stretch during use and it is necessary to frequently stop operation of the delimber to properly retension the cables.